*{
    box-sizing:border-box ;
}
body{
    background:url(img/7cd48ff3f1eac8b803aa086fc2f505f4.jpg) no-repeat;
    background-attachment: fixed;
    color:white;
    position: relative;
}
#content{
    width:60%;
    margin-left: 30%;
    box-sizing: border-box;
}
#content:last-child{
    padding-bottom: 250px;
}
#content div{
    position: relative;
}
#chap1{
    top:0;
}
#chap2{
    top:150px;
}
#chap3{
    top:300px;
}
#chap4{
    top:450px;
}

#nav{
    left:5%;
    width:15%;
    top:100px;
    position: fixed;
    font-size: 25px;
}
li{
    color:white;
    list-style: none;
    line-height: 50px;
    border-bottom: 1px solid white;
}
a{
    text-decoration: none;
    color:white;
}
li:hover{
    border-bottom:5px solid yellowgreen;
}
#nav ul li a{
    transition: all .5s;
    -webkit-transition: all 0.5s;
}
#nav ul li a.scrolling{
    color:greenyellow;
    text-indent: 2em;
}